Health Topics

Diagnostic tests

Heart Health Tests
National Library of Medicine
Cardiac Test
Heart Test
Cardiac Diagnostic Tests

Heart diseases are the number one killer in the U.S. They are also a major cause of disability. If you do have a heart disease, it is important to find it early, when it is easier to treat. Blood tests and heart health tests can help find heart diseases or identify problems that can lead to heart diseases. There are several different types of heart health tests. Your doctor will decide which test or tests you need, based on your symptoms (if any), risk factors, and medical history.

Cardiac Catheterization

Cardiac catheterization is a medical procedure used to diagnose and treat some heart conditions. For the procedure, your doctor puts a catheter (a long, thin, flexible tube) into a blood vessel in your arm, groin, or neck, and threads it to your heart. The doctor can use the catheter to

  • Do a coronary angiography. This involves putting a special type of dye in the catheter, so the dye can flow through your bloodstream to your heart. Then your doctor takes x-rays of your heart. The dye allows your doctor to see your coronary arteries on the x-ray, and to check for coronary artery disease (plaque buildup in the arteries).
  • Take samples of blood and heart muscle
  • Do procedures such as minor heart surgery or angioplasty, if your doctor finds that you need it
Cardiac CT Scan

A cardiac CT (computed tomography) scan is a painless imaging test that uses x-rays to take detailed pictures of your heart and its blood vessels. Computers can combine these pictures to create a three-dimensional (3D) model of the whole heart. This test can help doctors detect or evaluate

  • Coronary artery disease
  • Calcium buildup in the coronary arteries
  • Problems with the aorta
  • Problems with heart function and valves
  • Pericardial diseases

Before you have the test, you get an injection of contrast dye. The dye highlights your heart and blood vessels in the pictures. The CT scanner is a large, tunnel-like machine. You lie still on a table which slides you into the scanner, and the scanner takes the pictures for about 15 minutes.

Cardiac MRI

Cardiac MRI (magnetic resonance imaging) is a painless imaging test that uses radio waves, magnets, and a computer to create detailed pictures of your heart. It can help your doctor figure out whether you have heart disease, and if so, how severe it is. A cardiac MRI can also help your doctor decide the best way to treat heart problems such as

  • Coronary artery disease
  • Heart valve problems
  • Pericarditis
  • Cardiac tumors
  • Damage from a heart attack

The MRI is a large, tunnel-like machine. You lie still on a table which slides you into the MRI machine. The machine makes loud noises as it takes pictures of your heart. It usually takes about 30-90 minutes. Sometimes before the test, you might get an injection of contrast dye. The dye highlights your heart and blood vessels in the pictures.

Chest X-Ray

A chest x-ray creates pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. It can reveal signs of heart failure, as well as lung disorders and other causes of symptoms not related to heart disease.

Coronary Angiography

Coronary angiography (angiogram) is a procedure that uses contrast dye and x-ray pictures to look at the insides of your arteries. It can show whether plaque is blocking your arteries and how severe the blockage is. Doctors use this procedure to diagnose heart diseases after chest pain, sudden cardiac arrest, or abnormal results from other heart tests such as an EKG or a stress test.

You usually have a cardiac catheterization to get the dye into your coronary arteries. Then you have special x-rays while the dye is flowing through your coronary arteries. The dye lets your doctor study the flow of blood through your heart and blood vessels.

Echocardiography

Echocardiography, or echo, is a painless test that uses sound waves to create moving pictures of your heart. The pictures show the size and shape of your heart. They also show how well your heart's chambers and valves are working. Doctors use an echo to diagnose many different heart problems, and to check how severe they are.

For the test, a technician applies gel to your chest. The gel helps sound waves reach your heart. The technician moves a transducer (wand-like device) around on your chest. The transducer connects to a computer. It transmits ultrasound waves into your chest, and the waves bounce (echo) back. The computer converts the echoes into pictures of your heart.

Electrocardiogram (EKG), (ECG)

An electrocardiogram, also called an ECG or EKG, is a painless test that detects and records your heart's electrical activity. It shows how fast your heart is beating and whether its rhythm is steady or irregular.

An EKG may be part of a routine exam to screen for heart disease. Or you may get it to detect and study heart problems such as heart attacks, arrhythmia, and heart failure.

For the test, you lie still on a table and a nurse or technician attaches electrodes (patches that have sensors) to the skin on your chest, arms, and legs. Wires connect the electrodes to a machine that records your heart's electrical activity.

Stress Testing

Stress testing looks at how your heart works during physical stress. It can help to diagnose coronary artery disease, and to check how severe it is. It can also check for other problems, including heart valve disease and heart failure.

For the test, you exercise (or are given medicine if you are unable to exercise) to make your heart work hard and beat fast. While this is happening, you get an EKG and blood pressure monitoring. Sometimes you may also have an echocardiogram, or other imaging tests such as a nuclear scan. For the nuclear scan, you get an injection of a tracer (a radioactive substance), which travels to your heart. Special cameras detect the energy from the tracer to make pictures of your heart. You have pictures taken after you exercise, and then after you rest.

NIH: National Heart, Lung, and Blood Institute


Diagnostic Techniques, Cardiovascular
Heart Function Tests
Blood, Heart and Circulation
Heart diseases are the number one killer in the U.S. They are also a major cause of disability. If you do have a heart disease, it is important to find it ...
Prenatal Testing
National Library of Medicine
Amniocentesis
Chorionic Villi Sampling
Fetal Ultrasound

Prenatal testing provides information about your baby's health before he or she is born. Some routine tests during pregnancy also check on your health. At your first prenatal visit, your health care provider will test for a number of things, including problems with your blood, signs of infections, and whether you are immune to rubella (German measles) and chickenpox.

Throughout your pregnancy, your health care provider may suggest a number of other tests, too. Some tests are suggested for all women, such as screenings for gestational diabetes, Down syndrome, and HIV. Other tests might be offered based on your

  • Age
  • Personal or family health history
  • Ethnic background
  • Results of routine tests

There are two types of tests:

  • Screening tests are tests that are done to see if you or your baby might have certain problems. They evaluate risk, but do not diagnose problems. If your screening test result is abnormal, it does not mean that there is a problem. It means that more information is needed. Your health care provider can explain what the test results mean and possible next steps. You may need diagnostic testing.
  • Diagnostic tests show whether or not you or your baby have a certain problem.

It is your choice whether or not to get the prenatal tests. You and your health care provider can discuss the risks and benefits of the tests, and what kind of information the tests can give you. Then you can decide which ones are right for you.

Dept. of Health and Human Services Office on Women's Health


Prenatal Diagnosis
Pregnancy and Reproduction
Genetics/Birth Defects
Diagnostic Tests
Female Reproductive System
... Your health care provider can explain what the test results mean and possible next steps. You may need diagnostic testing. Diagnostic tests show whether or not you ...
Genetic Testing
National Library of Medicine
Paternity Testing

Genetic tests are tests on blood and other tissue to find genetic disorders. Over 2000 tests are available. Doctors use genetic tests for several reasons. These include

  • Finding genetic diseases in unborn babies
  • Finding out if people carry a gene for a disease and might pass it on to their children
  • Screening embryos for disease
  • Testing for genetic diseases in adults before they cause symptoms
  • Making a diagnosis in a person who has disease symptoms
  • Figuring out the type or dose of a medicine that is best for a certain person

People have many different reasons for being tested or not being tested. For some, it is important to know whether a disease can be prevented or treated if a test is positive. In some cases, there is no treatment. But test results might help a person make life decisions, such as family planning or insurance coverage. A genetic counselor can provide information about the pros and cons of testing.

NIH: National Human Genome Research Institute


Genetic Testing
Pregnancy and Reproduction
Genetics/Birth Defects
Diagnostic Tests
... Over 2000 tests are available. Doctors use genetic tests for several ... symptoms Making a diagnosis in a person who has disease symptoms Figuring ...
Health Screening
National Library of Medicine
Screening Tests

Screenings are tests that look for diseases before you have symptoms. Screening tests can find diseases early, when they're easier to treat. You can get some screenings in your doctor's office. Others need special equipment, so you may need to go to a different office or clinic.

Some conditions that doctors commonly screen for include

  • Breast cancer and cervical cancer in women
  • Colorectal cancer
  • Diabetes
  • High blood pressure
  • High cholesterol
  • Osteoporosis
  • Overweight and obesity
  • Prostate cancer in men

Which tests you need depends on your age, your sex, your family history, and whether you have risk factors for certain diseases. After a screening test, ask when you will get the results and whom to talk to about them.

Agency for Healthcare Research and Quality


Diagnostic Tests, Routine
Wellness and Lifestyle
Screenings are tests that look for diseases before you have symptoms. Screening tests can find diseases early, when they're easier to treat. You can get some screenings ...
Diagnostic Imaging
National Library of Medicine
Imaging

Diagnostic imaging lets doctors look inside your body for clues about a medical condition. A variety of machines and techniques can create pictures of the structures and activities inside your body. The type of imaging your doctor uses depends on your symptoms and the part of your body being examined. They include

  • X-rays
  • CT scans
  • Nuclear medicine scans
  • MRI scans
  • Ultrasound

Many imaging tests are painless and easy. Some require you to stay still for a long time inside a machine. This can be uncomfortable. Certain tests involve exposure to a small amount of radiation.

For some imaging tests, doctors insert a tiny camera attached to a long, thin tube into your body. This tool is called a scope. The doctor moves it through a body passageway or opening to see inside a particular organ, such as your heart, lungs, or colon. These procedures often require anesthesia.


Diagnostic Imaging
Diagnostic Tests
... a small amount of radiation. For some imaging tests, doctors insert a tiny ... as your heart, lungs, or colon. These procedures often require anesthesia.
A1C
National Library of Medicine
Hemoglobin A1c
Glycohemoglobin
HbA1C
Hemoglobin A1C test

A1C is a blood test for type 2 diabetes and prediabetes. It measures your average blood glucose, or blood sugar, level over the past 3 months. Doctors may use the A1C alone or in combination with other diabetes tests to make a diagnosis. They also use the A1C to see how well you are managing your diabetes. This test is different from the blood sugar checks that people with diabetes do every day.

Your A1C test result is given in percentages. The higher the percentage, the higher your blood sugar levels have been:

  • A normal A1C level is below 5.7 percent
  • Prediabetes is between 5.7 to 6.4 percent. Having prediabetes is a risk factor for getting type 2 diabetes. People with prediabetes may need retests every year.
  • Type 2 diabetes is above 6.5 percent
  • If you have diabetes, you should have the A1C test at least twice a year. The A1C goal for many people with diabetes is below 7. It may be different for you. Ask what your goal should be. If your A1C result is too high, you may need to change your diabetes care plan.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Glycated Hemoglobin A
Diagnostic Tests
Diabetes Mellitus
... A1C alone or in combination with other diabetes tests to make a diagnosis. They also use the A1C to see how well you are managing your diabetes. This test is different from the blood sugar checks that ...
Liver Function Tests
National Library of Medicine
Hepatic Function Panel
Liver panel
Liver tests

Your liver helps your body digest food, store energy, and remove poisons. Liver function tests are blood tests that check to see how well your liver is working. They check for liver damage, and can help diagnose liver diseases such as hepatitis and cirrhosis. You may have liver function tests as part of a regular checkup. Or you may have them if you have symptoms of liver disease. Doctors also use the tests to monitor some liver diseases, treatments, and possible side effects of medicines.

Liver function tests measure certain proteins, enzymes, and substances, including:

  • Albumin, a protein that the liver makes
  • Total protein (TP)
  • Enzymes that are found in the liver, including alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transpeptidase (GGT)
  • Bilirubin, a yellow substance that is part of bile. It is formed when your red blood cells break down. Too much bilirubin in the blood can cause jaundice. There is also a urine test for bilirubin.
  • Prothrombin time, which measures how long it takes for your blood to clot. Prothrombin is made by the liver.

Liver Function Tests
Digestive System
Diagnostic Tests
Your liver helps your body digest food, store energy, and remove poisons. Liver function tests are blood tests that check to see how well your liver is working. ...
Thyroid Tests
National Library of Medicine
Thyroid panel

Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones control the rate of many activities in your body. They include how fast you burn calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. They are also used to diagnose and help find the cause of thyroid diseases such as hyperthyroidism and hypothyroidism. Thyroid tests include blood tests and imaging tests.

Blood tests for your thyroid include

  • TSH - measures thyroid-stimulating hormone. It is the most accurate measure of thyroid activity.
  • T3 and T4 - measure different thyroid hormones.
  • TSI - measures thyroid-stimulating immunoglobulin.
  • Antithyroid antibody test - measures antibodies (markers in the blood).

Imaging tests include CT scans, ultrasound, and nuclear medicine tests. One type of nuclear medicine test is the thyroid scan. It uses small amounts of radioactive material to create a picture of the thyroid, showing its size, shape, and position. It can help find the cause of hyperthyroidism and check for thyroid nodules (lumps in the thyroid). Another nuclear test is the radioactive iodine uptake test, or thyroid uptake test. It checks how well your thyroid is working and can help find the cause of hyperthyroidism.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Thyroid Function Tests
Endocrine System
Diagnostic Tests
Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones ...
Hepatitis Testing
National Library of Medicine
Hepatitis panel

Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. Hepatitis is an inflammation of the liver. There are different types of hepatitis. Some are caused by viruses. They include hepatitis A, hepatitis B, and hepatitis C. To diagnose hepatitis, your health care provider will ask you about your medical history and symptoms, do a physical exam, and order blood tests.

There are blood tests for each type of viral hepatitis. Some tests check for antibodies to the virus. Antibodies are blood proteins that your immune system makes in response to the virus. Other blood tests look for parts of the virus, such as proteins or genetic material. Some tests show that you have the infection now. Other tests show that you have had it at some time, or that you have immunity to it.

Doctors use the tests to diagnose hepatitis, and to screen people who are at risk for hepatitis B or C. The risk factors are different for each type. Doctors may also use the tests in people who have hepatitis, to check how contagious they are or to see how well treatment is working.


Hepatitis
Digestive System
Infections
Diagnostic Tests
Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. Hepatitis is an inflammation of the liver. ...
Kidney Tests
National Library of Medicine
Kidney Biopsy
Kidney Function Tests
Kidney Function Panel
Kidney Panel
Renal Function Panel

You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. Your kidneys filter and clean your blood, taking out waste products and making urine. Kidney tests check to see how well your kidneys are working. They include blood, urine, and imaging tests.

Early kidney disease usually does not have signs or symptoms. Testing is the only way to know how your kidneys are doing. It is important for you to get checked for kidney disease if you have the key risk factors - diabetes, high blood pressure, heart disease, or a family history of kidney failure.

Specific kidney tests include

  • Glomerular filtration rate (GFR) - one of the most common blood tests to check for chronic kidney disease. It tells how well your kidneys are filtering.
  • Creatinine blood and urine tests - check the levels of creatinine, a waste product that your kidneys remove from your blood
  • Albumin urine test - checks for albumin, a protein that can pass into the urine if the kidneys are damaged
  • Imaging tests, such as an ultrasound - provide pictures of the kidneys. The pictures help the health care provider see the size and shape of the kidneys, and check for anything unusual.
  • Kidney biopsy - a procedure that involves taking a small piece of kidney tissue for examination with a microscope. It checks for the cause of kidney disease and how damaged your kidneys are.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Kidney Function Tests
Kidneys and Urinary System
Diagnostic Tests
You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. Your kidneys filter and clean your blood, taking out waste ...